Russia's Federal Security Service (FSB) has announced the "neutralization" of Chechen militant leader Doku Umarov's "activities."

FSB Director Aleksandr Bortnikov made the announcement on April 8, saying the "activities" of self-proclaimed Caucasus Emirate leader Umarov were "neutralized" earlier this year.

Bortnikov did not elaborate, saying just that 33 special combat operations against Islamic insurgents had been conducted in the North Caucasus, in which 36 leaders and 65 members of religious extremist groups had been killed and 200 terrorists had been arrested.

A video clip posted on March 18 showed Aliasaskhab Kebekov (aka Ali Abu-Mukhammad), the supreme religious authority of the Caucasus Emirate proclaimed in 2007 by then-Chechen Republic Ichkeria President Doku Umarov, claiming he had been chosen to succeed Umarov as Caucasus Emirate leader.

He said he was appointed by a six-member "shura," or council.

Umarov has been linked to a series of bombings across Russia, including Moscow.